124,351 research outputs found
su(2) and su(1,1) displaced number states and their nonclassical properties
We study su(2) and su(1,1) displaced number states. Those states are
eigenstates of density-dependent interaction systems of quantized radiation
field with classical current. Those states are intermediate states
interpolating between number and displaced number states. Their photon number
distribution, statistical and squeezing properties are studied in detail. It is
show that these states exhibit strong nonclassical properties.Comment: 10 pages, 3 figure
Topological phase transitions in multi-component superconductors
We study the phase transition between a trivial and a time-reversal-invariant
topological superconductor in a single-band system. By analyzing the interplay
of symmetry, topology and energetics, we show that for a generic normal state
band structure, the phase transition occurs via extended intermediate phases in
which even- and odd-parity pairing components coexist. For inversion-symmetric
systems, the coexistence phase spontaneously breaks time-reversal symmetry. For
noncentrosymmetric superconductors, the low-temperature intermediate phase is
time-reversal breaking, while the high-temperature phase preserves
time-reversal symmetry and has topologically protected line nodes. Furthermore,
with approximate rotational invariance, the system has an emergent symmetry, and novel topological defects, such as half vortex lines
binding Majorana fermions, can exist. We analytically solve for the dispersion
of the Majorana fermion and show that it exhibit small and large velocities at
low and high energies. Relevance of our theory to superconducting pyrochlore
oxide CdReO and half-Heusler materials is discussed.Comment: 14 pages, 7 figures; to appear on Phys. Rev. Let
Excitation function of initial temperature of heavy flavor quarkonium emission source in high energy collisions
The transverse momentum spectra of , , and produced in proton-proton (+), proton-antiproton
(+), proton-lead (+Pb), gold-gold (Au+Au), and lead-lead (Pb+Pb)
collisions over a wide energy range are analyzed by the (two-component) Erlang
distribution, the Hagedorn function (the inverse power-law), and the
Tsallis-Levy function. The initial temperature is obtained from the color
string percolation model due to the fit by the (two-component) Erlang
distribution in the framework of multisource thermal model. The excitation
functions of some parameters such as the mean transverse momentum and initial
temperature increase from dozens of GeV to above 10 TeV. The mean transverse
momentum and initial temperature decrease (increase slightly or do not change
obviously) with the increase of rapidity (centrality). Meanwhile, the mean
transverse momentum of is larger than that of
and , and the initial temperature for
emission is higher than that for and emission, which shows
a mass-dependent behavior.Comment: 26 pages, 12 figures. Advances in High Energy Physics, accepte
Intrinsic coherence in assisted sub-state discrimination
We study intrinsic coherence in the tripartite process to unambiguously
discriminate two nonorthogonal states of a qubit, entangled with another one,
and assisted by an auxiliary system. The optimal success probability is found
to be benefited by initial intrinsic coherence, but no extra one is required.
The transformations among different contributions of intrinsic coherence are
necessary in this procedure, which increase with the overlap between the states
to recognize. Such state discrimination is a key step of the probabilistic
teleportation protocol. Entanglement of the quantum channel decreases the
coherence characterizing the reliance on an ancilla.Comment: 6 pages with 4 figure
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